Try them all...
I've tried about everything to get that elusive conga natural sound.
Every thing from an overhead drum mic to close micing with 57's or better with my favorite, Behringer C-2's at about 6" off the front at an angle.
I also use the sweep mids to drop the bottom lots of mids and highs, run it threw a fast decay slap back verb, and it sounds like a conga only amplified... I think.
Now for a drumming party with you can add a 57 underneith, but this is only if you need some bottom, like an acoustic set up with only conga's as rythem.